Living Off the Grid

The "Grid" is the network of wires that supply most of today's
people with electricity and communications. Here on the Big Island,
the grid generally follows the main highway that belts the island. From
there it branches into some communities, however, it does not go
everywhere. Living off the grid simply means that you do not depend
upon it for electricity or phone/internet service. Some people live
off the grid because it is too far away, while others choose to let it
pass them by for independence, economic, and environmental reasons.
Living without utility supplied electricity can be challenging for those
of us who have come to take it so for granted, but it is an
option.

Hawaii is a prime location for alternative energy
enthusiasts. The climate, (at least at moderate and low elevations), is very
hospitable to humans. We need not expend huge amounts of energy to warm up
or keep cool. People travel from all over the world to grab a little
Hawaiian sunshine, which is usually available in some abundance in most
areas. The low latitude of Hawaii means that the winter Sun will never
ride so low in the sky as to not be useful for energy production. Some
areas of South Hawaii are known for their windiness. Commercial wind
powered electric generators are found on the South Point peninsula.

Solar Water Heaters
Consider that the overhead Sun sheds about 750 Watts of power (broad spectrum) on to every square
meter of Earth surface. That's a lot of juice! Unfortunately we humans
have yet to figure a way to capture most of that. A fairly efficient
capture system is to paint a surface black and just have the Sun heat it. You
can run water across this hot black surface (usually within a pipe) and you have
a solar water heater. Real solar water heaters usually have an insulated
storage tank to hold the hot water after the Sun goes down. Solar water
heaters are fairly common in Hawaii. Even if you are on the grid you may
consider a solar water heater. The electric
utility offers sizable rebates on your installation of an approved system by
certain contractors. One word of caution; investigate how much Sun your
property actually receives. Many higher elevation locations cloud over
almost daily due to clouds that form around our mountains. This daily cloud
effect may impact your solar energy collecting ability.

Photovoltaic Energy
You have probably heard of solar cells. You may have owned a calculator or
some other device that used these to charge its battery. Large collections
of solar cells (a solar panel) can be used to convert the Sun's energy directly
into electricity and charge a battery. The battery can then be used to
power lights, entertainment equipment, or most anything electrical. One
problem with solar cells is that they are quite inefficient , that is, they can
only convert a small portion (about 15%) of the sunlight they receive into
electricity. That 750 watts of available Sun power per square meter ends up
being about 100 Watts of electricity. This could be overcome by
using a huge number of solar cells. That, however, is problematic because
solar panels are still quite expensive. What most people do is buy as
large a system as their budget will allow and then use the collected energy very
frugally.

Wind Energy
As mentioned above, there are commercial wind powered electric generators here
in Hawaii powered by the plentiful wind found in some areas. The south
part of the Big Island, especially the southern Kau district is known for its
windiness. Wind powered electric generators can be purchased for home use.
You should be able to purchase a small wind generator somewhere in the $600
range that produces up to 400 watts of electricity (when the wind is blowing!) . That
compares quite favorably to solar panels. On the down side, wind generators have
moving parts and moving parts all eventually wear out. Still, wind
generators work when the Sun isn't shining and combining a wind generator system
with a photovoltaic system is a popular choice among many off griders.

Batteries
If you produce your own electricity from photovoltaic panels or wind generators,
you will need to store the energy in batteries. These are usually deep
cycle lead acid batteries (12 Volt). This means your available electricity
is in the form of direct current (DC). In order to power your alternating current (AC)
appliances, the DC from the batteries has to be converted to AC using a device
known as a power inverter. Power inverters have an efficiency problem of their own. They are not 100%
efficient in the converting process and always lose some energy as heat.
It is thus advisable to avoid using them where possible by utilizing 12 Volt DC
appliances, and lights. These are fairly common as they have had a long
term usage in the RV world. Batteries require periodic replacement, are
fairly expensive, and pose environmental problems. Alas, there is no
perfect solution.

Fossil Fuels
Most people who have solar energy systems have a gasoline powered generator to
help supplement their energy needs. The generator is usually placed in a sound baffling
box some distance from the house. Gas generators are noisy and expensive to run,
but you will probably want one if you live off the grid. Many people use
propane for water heating, cooking, and even refrigeration. Propane can be
purchased from several distribution points and delivery is available.

Experts
We are lucky to have alternative power specialists right
in Ocean View at Solar Works. Dan and
Donna Durgin have been helping people live off the grid here for years. Check
with them for some real expertise. Note that home wiring in Hawaii is
legally done only by a licensed electrician. Low voltage wiring has its
own requirements and potential hazards. Get advice from an expert!